using ...

[assembly: OwinStartup(typeof (Startup))]

namespace Mafly.OAuth2._0.Demo
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            // 有关如何配置应用程序的详细信息，请访问 http://go.microsoft.com/fwlink/?LinkID=316888
            var config = new HttpConfiguration();
            WebApiConfig.Register(config);

            //开启OAuth服务
            ConfigureOAuth(app);

            app.UseWebApi(config);
        }

        public void ConfigureOAuth(IAppBuilder app)
        {
            // Token 生成配置
            var oAuthOptions = new OAuthAuthorizationServerOptions
            {
                AllowInsecureHttp = true, //允许客户端使用Http协议请求
                AuthenticationMode = AuthenticationMode.Active,
                TokenEndpointPath = new PathString("/token"), //请求地址
                AccessTokenExpireTimeSpan = TimeSpan.FromHours(2), //token过期时间

                //提供认证策略
                Provider = new OpenAuthorizationServerProvider()
                //RefreshTokenProvider = new RefreshAuthenticationTokenProvider()
            };
            app.UseOAuthBearerTokens(oAuthOptions);
        }
    }
}

public class OpenAuthorizationServerProvider : OAuthAuthorizationServerProvider
    {
        /// <summary>
        ///     验证客户端
        /// </summary>
        /// <param name="context"></param>
        /// <returns></returns>
        public override async Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
        {
            string clientId;
            string clientSecret;
            context.TryGetFormCredentials(out clientId, out clientSecret);
            //context.TryGetBasicCredentials(out clientId, out clientSecret); //Basic认证

            //TODO:读库，验证
            if (clientId != "malfy" && clientSecret != "111111")
            {
                context.SetError("invalid_client", "client is not valid");
                return;
            }
            context.OwinContext.Set("as:client_id", clientId);
            context.Validated(clientId);
        }

        /// <summary>
        ///     客户端授权[生成access token]
        /// </summary>
        /// <param name="context"></param>
        /// <returns></returns>
        public override Task GrantClientCredentials(OAuthGrantClientCredentialsContext context)
        {
            var oAuthIdentity = new ClaimsIdentity(context.Options.AuthenticationType);
            oAuthIdentity.AddClaim(new Claim(ClaimTypes.Name, context.OwinContext.Get<string>("as:client_id")));
            var ticket = new AuthenticationTicket(oAuthIdentity, new AuthenticationProperties {AllowRefresh = true});
            context.Validated(ticket);
            return base.GrantClientCredentials(context);
        }
    }